1. Field of the Invention
The present invention relates to a robot apparatus which can travel along the units of a double twister and relates to a new method of operating a robot apparatus for a double twister which forms full winding packages from a plurality of predetermined length feed packages.
2. Prior Art
A double twister is a device in which a yarn drawn out of a feed package supported on a spindle is threaded through a center hole thereof, and wound about a core supported on a cradle while applying a twist to form a winding package. When the core winds thereabout all the yarn of the feed package into a full winding package, an empty feed package is replaced with a full feed package (replacement of yarn), a yarn end is drawn out of the feed package (yarn end finding), the yarn is threaded into the center hole (threading), the full winding package is removed from the cradle and supported on a new paper tube (doffing) and the yarn end drawn out of the feed package is fixed (hooking) to the paper tube.
In the past, these operations have been carried out exclusively by an operator, which takes much time.
However, nowadays, frequencies of operations such as doffing, yarn replacement and the like increase with small-volume production of various kinds of products, and automation of the aforesaid operations has been desired in an attempt of relieving labor and improving productivity.
A double twister is a device in which in each unit, a yarn is released from a feed package supported on a spindle to apply a twist thereto, and the resultant yarn is wound on a core supported on a cradle to form a full winding package.
This double twister requires package replacement in which an empty feed package is replaced with a new feed package, yarn end finding for pulling out a yarn end from the new feed package, threading for threading the pulled out yarn end into a spindle from an axial hole thereof, doffing for removing the full winding package from the cradle and supporting a new core on the cradle, and hanging for fixing the yarn end after being threaded into the core. A robot for automatically performing these operations has been developed (Japanese Patent Laid Open Publication No. 243470/1990).
A conventional double twister has a construction in which a feed package and a winding package correspond in the form of 1:1. Therefore, a spindle portion should have a large construction corresponding to the size of the feed package. It has been difficult to provide an implementation for multi-unit by miniaturization of units.
In order to solve this problem, winding packages having a predetermined size (winding amount) may be formed from a plurality of feed packages. In this case, there is a problem in that a yarn length counter need be provided on the double twister.